5.10-stable review patch. If anyone has any objections, please let me know.
------------------
From: Heiko Carstens <hca@xxxxxxxxxxxxx>
[ Upstream commit 0147addc4fb72a39448b8873d8acdf3a0f29aa65 ]
Disable compile time optimizations of test_facility() for the
decompressor. The decompressor should not contain any optimized code
depending on the architecture level set the kernel image is compiled
for to avoid unexpected operation exceptions.
Add a __DECOMPRESSOR check to test_facility() to enforce that
facilities are always checked during runtime for the decompressor.
Reviewed-by: Sven Schnelle <svens@xxxxxxxxxxxxx>
Signed-off-by: Heiko Carstens <hca@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
arch/s390/include/asm/facility.h | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/arch/s390/include/asm/facility.h b/arch/s390/include/asm/facility.h
index 68c476b20b57e..c7031d9ada293 100644
--- a/arch/s390/include/asm/facility.h
+++ b/arch/s390/include/asm/facility.h
@@ -53,8 +53,10 @@ static inline int test_facility(unsigned long nr)
unsigned long facilities_als[] = { FACILITIES_ALS };
if (__builtin_constant_p(nr) && nr < sizeof(facilities_als) * 8) {
- if (__test_facility(nr, &facilities_als))
- return 1;
+ if (__test_facility(nr, &facilities_als)) {
+ if (!__is_defined(__DECOMPRESSOR))
+ return 1;
+ }
}
return __test_facility(nr, &S390_lowcore.stfle_fac_list);
}
--
2.43.0
